/*
 * DPVS is a software load balancer (Virtual Server) based on DPDK.
 *
 * Copyright (C) 2021 iQIYI (www.iqiyi.com).
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */
#include <endian.h>
#include <stdbool.h>
#include <arpa/inet.h>
#include "ipset/pfxlen.h"
/* Prefixlen maps for fast conversions, by Jan Engelhardt. */

#ifdef E
#undef E
#endif

#define PREFIXES_MAP						\
	E(0x00000000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0x80000000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xC0000000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xE0000000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xF0000000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xF8000000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFC000000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFE000000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFF000000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFF800000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFC00000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFE00000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFF00000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFF80000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFC0000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFE0000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFF0000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFF8000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFC000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFE000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFF000, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFF800, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFC00, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFE00, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFF00, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFF80, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFC0, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFE0, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFF0, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFF8, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFC, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFE, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0x00000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0x80000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xC0000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xE0000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xF0000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xF8000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFC000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFE000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFF000000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFF800000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFC00000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFE00000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFF00000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFF80000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFC0000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFE0000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFF0000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFF8000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFC000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFE000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFF000, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFF800, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFC00, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFE00, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFF00, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFF80, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFC0, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFE0, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFF0, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFF8, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFC, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFE, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0x80000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xC0000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xE0000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xF0000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xF8000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFC000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFE000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFF000000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFF800000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFC00000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFE00000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFF00000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFF80000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFC0000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFE0000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFF0000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFF8000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFC000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFE000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFF000, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFF800, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFC00, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFE00, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFF00, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFF80, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFC0, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFE0, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFF0, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFF8, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFC, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFE, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0x80000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xC0000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xE0000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xF0000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xF8000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFC000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFE000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFF000000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFF800000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFC00000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFE00000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFF00000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFF80000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFC0000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFE0000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFF0000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFF8000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFC000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFE000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFF000),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFF800),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFC00),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFE00),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFF00),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFF80),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFC0),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFE0),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFF0),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFF8),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFC),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFE),	\
	E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF),

#undef htonl
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define htonl(x) \
     ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) |		      \
      (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))
#else
#define htonl(x) (x)
#endif

#define E(a, b, c, d) \
	{.ip6 = { \
		htonl(a), htonl(b), \
		htonl(c), htonl(d), \
	} }

/* This table works for both IPv4 and IPv6;
 * just use prefixlen_netmask_map[prefixlength].ip.
 */
const union nf_inet_addr ip_set_netmask_map[] = {	
    PREFIXES_MAP
};

#undef htonl
#undef E

#define E(a, b, c, d)				\
	{.ip6 = { (__be32)a, (__be32)b,		\
		  (__be32)c, (__be32)d,		\
	} }

/* This table works for both IPv4 and IPv6;
 * just use prefixlen_hostmask_map[prefixlength].ip.
 */
const union nf_inet_addr ip_set_hostmask_map[] = {
    PREFIXES_MAP
};

static inline bool after(__u32 seq1, __u32 seq2)
{
    return (__s32)(seq1-seq2) > 0;
}

/* Find the largest network which matches the range from left, in host order. */
__u32
ip_set_range_to_cidr(__u32 from, __u32 to, __u8 *cidr)
{
    __u32 last;
    __u8 i;

    for (i = 0; i < 32; i++) {
        if ((from & ip_set_hostmask(i)) != from)
            continue;
        last = from | ~ip_set_hostmask(i);
        if (!after(last, to)) {
            *cidr = i;
            return last;
        }
    }
    *cidr = 32;
    return from;
}
